The two types of El-Nino and their impacts on the length of day

作者：de Viron O^*; Dickey J O

来源：Geophysical Research Letters, 2014, 41(10): 3407-3412.

DOI：10.1002/2014GL059948

• Earth rotation
• El Nino
• torque approach
• length of day

At the interannual to decadal time scale, the changes in the Earth rotation rate are linked with the El-Nino-Southern Oscillation phenomena through changes in the atmospheric angular momentum. As climatic studies demonstrate that there were two types of El-Nino events, namely, eastern Pacific (EP) and central Pacific (CP) events, we investigate how each of them affects the atmospheric angular momentum. We show in particular that EP events are associated with stronger variations of the atmospheric angular momentum and length of day. We explain this difference by the stronger pressure gradient over the major mountain ranges, due to a stronger and more efficiently localized pressure dipole over the Pacific Ocean in the case of EP events.

• 出版日期2014-5-28